Extech Light Meter FAQ,s

Q. Do you have a light meter that measures light pulses/flashes or strobes?

The Extech EasyView EA30 is the only model that can measure light pulses/flashes or strobes. It has a peak hold feature that can capture short light pulses as fast as 100µS (100 microseconds).

Q. Do you have a light meter that measures very high light levels?

Extech has Light Meters that can measure as high as 99,990Fc/999,900Lux with resolutions of 0.001Fc & 0.01 Lux. You can view the complete specifications of our light meters online. If you need more assistance, please contact our sales team.

Q. Do you have a meter that can measure coloured light and light forms other than visible light (LED’s/Blacklight/UV)?

All Extech light meters are designed to measure the intensity of visible light only (400 to 760µm). Extech does not have a product that can measure other forms of light (LED’s/Blacklight/UV etc.)

Q. What is the correct procedure to make measurements with my light meter?

The operation manual for your light meter will provide you with the basic information on how to make light measurements with your meter. Further light measuring procedures are outlined in local, state & federal lighting standards & compliance’s that are applicable to specific applications.

A Quick Look at Lux, Candle Power and Lumens

Candlepower is a measure of luminous intensity when specifically measured in units of candelas. This is like “mileage” is a measure of distance when the unit of measure is in miles. Luminous intensity is a measure of light [flux] passing through a unit of *solid angle*. A candela is the intensity produced where there is one lumen [flux]per steradian [the measure of solid angle].

Lux is a unit of measure of illumination which is a measure of light [flux] *falling on a flat area*. One lux is the illumination produced when there is one lumen [flux] falling on a square meter. Lumens are a measure of total light [flux]. Think of a focusable flashlight. As the beam is adjusted from broad to narrow, the total flux [lumens] stays the same but the illumination of a surface or intensity [lux or candelas] within the beam increases.

Illumination [Lux] or candlepower [candelas]can be measured with relatively simple instruments. Flux [lumens] is much more complicated. Most commonly an integrating sphere is used to capture all of the light emitted by a source and then the illumination is measured at a fixed point in the sphere. Through complicated calibrations this illumination measurement is then correlated with a flux value.